The present invention concerns a warning device for mounting onto a vehicle, in order to attract the driver""s attention by means of a signal when an object is located in a position that is wholly or partially critical for the driver.
When, for example, a second vehicle is located in a position diagonally behind xe2x80x9cone""s ownxe2x80x9d vehicle, normally in a position diagonally behind one""s own vehicle relative to the position of the driving seat, it can be difficult to perceive the second vehicle in the rear-view mirror, even if this is correctly aligned. It becomes even more difficult if the mirror is somewhat wrongly aligned. Furthermore, the construction of the vehicle normally prevents the peripheral vision of the eye from perceiving the second vehicle when the driver looks in the rear-view mirror. A further factor that makes it difficult to discover the second vehicle in this position is the stress to which the vehicle driver is exposed when driving in heavy traffic, with the requirement for repeated lane-changes, as is particularly the case in city traffic.
The Swedish patent application 9700276-0 (also published as WO 98/34131) submitted by the same applicant as the present application specifies a warning device for mounting onto a vehicle in order to attract the driver""s attention by means of a signal when an object is located in a position that is critical for the driver. The device comprises two sources of laser radiation arranged at a distance from each other, a convex lens arranged outside of each source, and a position-sensitive radiation detector arranged between the sources, outside of which is also arranged a convex lens. The sources and the detector are part of an integrated current circuit with the sources modulated to be activated with a phase displacement and the beams from the sources are adjusted to intersect each other at a predetermined distance from the device.
Other more or less sophisticated devices are available to warm the driver about other vehicles that are present in the said xe2x80x9cblind spotxe2x80x9d, that is, diagonally behind one""s own vehicle.
The following documents, U.S. Pat. Nos. 3,732,536; 3,568,144; GB 22 65 744 and WO 95/25322, are a selection of those that concern vehicle detection devices for detecting the presence of a vehicle within the said xe2x80x9cblind spotxe2x80x9d, that is, diagonally behind the vehicle that possesses the said device, by the use of passive ultrasound reception or heat-detection (IR) arrangements. The components that are part of the arrangements are often arranged at different locations on the vehicles. Against the background of the surrounding background radiation noise, it is essentially impossible to make this type of equipment reliable as a warning device of the intended type.
A device is revealed in DE-2455733 for the measurement of the relative distance to an object that determines the distance to the object independently of whether the object is close to or far from the device.
Devices equipped with active search means for the discovery of a second vehicle diagonally behind one""s own are also known. These active search means thus consist of some type of transmitter of pulses and receivers for the reception of echoes, which are obtained if the pulses impinge upon an object in their pathway. Examples of such devices are shown in DE-21 43 406 and in EP 0 370 965 A2, which devices use Doppler radar. The complexity of these known devices and the relatively high costs that are thus associated with them, combined with a large risk for interruptions in service, have resulted in these known warning devices not having found a market. There is a large risk that false echoes are received.
A warning device is known through GB 2283874 that attracts the driver""s attention, for example, through sensing the direction indicator and the angle of the wheels through sensors for the same.
The document WO 9013103 displays a warning device for attracting the attention of the driver of a vehicle in which detectors are arranged at the rear or side sections of a vehicle, and where the vehicle is a lorry.
A warning device for attracting the attention of the driver of a vehicle that takes the speed of the vehicle into consideration is known through the document JP 9132094 through Derwents"" abstract 1997-328064.
However, none of the above-mentioned documents describe a warning device in the form of a rear-view mirror for vehicles that emits a signal with the status of a warning with respect to sensors for the direction indicators, deviation of wheel angle, threshold detection of the speed of the vehicle in combination with input signals from other sensors.
Further, it is desirable that the vehicle does not emit a warning signal during normal turning in, for example, a roundabout or when turning corners to the right or left.
The present invention involves a warning device that draws the driver""s attention to the critical position of second vehicle or object relative to the vehicle of the driver, without the position determination being disturbed by background noise or sunlightxe2x80x94background lightxe2x80x94, while at the same time being reliable and easy to keep clean.
A warning device according to the present invention will with very great probability save many lives and prevent or guard against traffic injuries. The problem of what is known as the xe2x80x9cblind spotxe2x80x9d is one to which motorists are exposed every day.
There is currently no warning device in the form of a rear-view mirror that is sufficiently advanced to take into consideration all of the sensor outputs, at one and the same time, that are described in the three documents GB 2283874, WO 9013103 and JP 9132094, and that in addition takes into account that an alarm is not to be emitted when turning a corner.
Hereby the present invention specifies a warning device in the form of a rear-view mirror for mounting onto a vehicle, in order to attract the driver""s attention by means of a signal when an object is located in a position that is wholly or partially critical for the driver. The device comprises at least one source of electromagnetic radiation or ultrasound together with an arranged position-sensitive radiation- or sound detector.
The source and the detector are parts of an electronic circuit, whereby the detector detects the presence of an object in a position that is critical for the driver. One output in the circuit for a first signal with the status of a warning is activated, whereby a first-level warning signal is emitted.
The electronic circuit for the warning device comprises the following sensor means with associated outputs for the activation of signals with the status of a warning:
sensor means for detection of an input signal on/off from the direction indicators of the vehicle;
output in the circuit for activation of a signal with the status of a warning when the input signal of the direction indicator is on;
sensor devices that detect an angular deviation of one of the wheels of the vehicle;
outputs in the circuit for activation of a signal with the status of a warning when the warning signal is emitted for angular deviation;
means for determining the speed of the vehicle; and
threshold detection means for speeds, whereby predetermined threshold values of speed emit a signal with the status of a warning in combination with input signals from sensor means in the direction of motion of the vehicle depending on the detection by the sensor means and that a maximum angular deviation is specified, which determines that the vehicle is turning a corner, turning left or right, etc.
In one embodiment of the invention, a further level of signals with the status of a warning is achieved with the sensor means for the direction indicator.
Another embodiment of the invention specifies that a further level of signals with the status of a warning is achieved with the sensor means for angular deviation.
Yet another embodiment specifies that a further level of signals with the status or a warning is achieved with sensor means and detection of speed depending on the threshold value.
The detection of speed is deactivated in one embodiment of the invention when the speed falls below a predetermined minimum speed.
If the speed of the vehicle is lower than a predetermined maximum speed, a further level is activated according to one embodiment of the invention for change of lane or over-taking through detection from sensor means for the direction indicators and/or angular deviation.
A further embodiment of the invention specifies that a further level is activated if the detection of angular deviation is greater than a predetermined angle when the speed is greater than a predetermined minimum speed.
If the speed of the vehicle is greater than a predetermined maximum speed, a further level is activated when the sensor means for direction indicators detects that the input signal is on, in one embodiment of the invention. A further level is activated in one embodiment when the sensor means detects an angular deviation.
In one preferred embodiment of the device, it is contained within a rear-view mirror for a vehicle. The rear-view mirror contains a battery for the operation of the device in a further embodiment of the invention.
The detector is mounted in one embodiment of the invention on the rear section of the vehicle. The detector is mounted in a rear-view mirror and a further detector is mounted on the rear section of a vehicle according to one embodiment in which the detectors collaborate in order to detect reflected signals that are received.
A further embodiment includes the mounting on the side section of a vehicle of at least one detector for the detection of reflected signals.
The vehicle in one embodiment with detectors mounted on the side or rear sections is a truck or similar vehicle.